Effect of prophylactic antiviral intervention on T cell immunity in hepatitis B virus-infected pregnant women.

BACKGROUND: Antiviral intervention in hepatitis B virus (HBV)-infected pregnant women can effectively reduce mother-to-child transmission. However, the immunological characteristics of pregnant women with chronic HBV infection and the effects of antiviral intervention during pregnancy on maternal immune response remain unknown. We aimed to investigate these effects by comparing mothers who received antiviral intervention during pregnancy with those who did not. METHODS: Pregnant women positive for hepatitis B surface antigen and hepatitis B e-antigen (HBsAg+ HBeAg+) were enrolled at delivery, including 34 received prophylactic antiviral intervention during pregnancy (AVI mothers) and 15 did not (NAVI mothers). T lymphocyte phenotypes and functions were analysed using flow cytometry. RESULTS: At delivery, maternal regulatory T cell (Treg) frequency in AVI mothers was significantly higher than that in NAVI mothers (P < 0.002), and CD4+ T cells in AVI mothers displayed a decreased ability to secrete IFN-γ (P = 0.005) and IL-21 (P = 0.043), but an increased ability to secrete IL-10 and IL-4 (P = 0.040 and P = 0.036), which represented a higher Treg frequency, enhanced Th2 response and suppressed Th1 response. Treg frequency among AVI mothers was correlated negatively with serum HBsAg and HBeAg levels. After delivery, the ability of CD4+ T cells or CD8+ T cells to secrete IFN-γ or IL-10 was similar and no significant difference in Treg frequency was found between the two groups. CONCLUSIONS: Prophylactic antiviral intervention during pregnancy has an effect on T cell immunity in pregnant women, which was characterised by increased maternal Treg frequency, enhanced Th2 response and suppressed Th1 response at delivery.

Wavelength-tunable L-band mode-locked fiber laser using a long-period fiber grating.

We demonstrate an L-band wavelength-tunable passively mode-locked fiber laser using a single long-period fiber grating (LPFG) as a narrow-band optical attenuator (NBOA). Through bending the LPFG, the central wavelength can be continuously tuned from 1582.02 to 1597.29 nm, while the output power only varies from 1.465 to 1.057 mW, approximately a rate of 22 µW/nm variation. This is the first time that LPFG is functioned as a NBOA in mode-locked fiber lasers, showing the great advantage of less impact on output power variation reduction. Besides, the total cavity length is 5.08 m, which is the shortest length yet reported in wavelength-tunable mode-locked fiber lasers. The wavelength tuning could also be realized at harmonic mode locking with tuning range of 14.69 nm under 5th harmonic.

Effects of intrauterine exposure to maternal-derived HBeAg on T cell immunity in cord blood.

Immature immune system and immune tolerance induced by exposure to HBeAg in utero and/or shortly after infection in newborns were reportedly the causes of chronic HBV infection. To investigate the effect of maternal-derived HBeAg on neonatal T cell immunity, we analysed and compared T cell phenotypes and functions among neonates born to HBsAg+ /HBeAg+ mothers (HBeAg+ neonates), HBsAg+ /HBeAg- mothers (HBeAg- neonates) and healthy control mothers (HC neonates), using flow cytometry. The results showed that neonatal T cell phenotypes were similar regardless of HBeAg exposure. Upon anti-CD3 and anti-CD28 stimulation in HBeAg+ neonates, CD4+ T cell production of IFN-γ (P < .05) was significantly enhanced, while CD8+ T cells secreted significantly more IL-2 compared with those in HBeAg- and HC groups (P < .05). Moreover, similar levels of IFN-γ and IL-10 were observed in the culture supernatant after stimulation with rHBsAg, rHBcAg or rHBeAg among HBeAg+ , HBeAg- and HC neonates, whereas HBeAg+ neonates produced more TNF-α than HBeAg- neonates upon stimulation with rHBcAg. In conclusion, the results indicated that the HBsAg+ /HBeAg+ maternal environment did not influence the phenotypes of cord blood T cells but boosted neonatal non-specific Th1-type cytokine production.

Deletion of a flippase subunit Tmem30a in hematopoietic cells impairs mouse fetal liver erythropoiesis.

Transmembrane protein 30A (Tmem30a) is the ß-subunit of P4-ATPases which function as flippase that transports aminophospholipids such as phosphatidylserine from the outer to the inner leaflets of the plasma membrane to maintain asymmetric distribution of phospholipids. It has been documented that deficiency of Tmem30a led to exposure of phosphatidylserine. However, the role of Tmem30a in vivo remains largely unknown. Here we found that Vav-Cre-driven conditional deletion of Tmem30a in hematopoietic cells led to embryonic lethality due to severe anemia by embryonic day 16.5. The numbers of erythroid colonies and erythroid cells were decreased in the Tmem30a deficient fetal liver. This was accompanied by increased apoptosis of erythroid cells. Confocal microscopy analysis revealed an increase of localization of erythropoietin receptor to areas of membrane raft microdomains in response to erythropoietin stimulation in Ter119-erythroid progenitors, which was impaired in Tmem30a deficient cells. Moreover, erythropoietin receptor (EPOR)-mediated activation of the STAT5 pathway was significantly reduced in Tmem30a deficient fetal liver cells. Consistently, knockdown of TMEM30A in human CD34+ cells also impaired erythropoiesis. Our findings demonstrate that Tmem30a plays a critical role in erythropoiesis by regulating the EPOR signaling pathway through the formation of membrane rafts in erythroid cells.

Using threshold regression to analyze survival data from complex surveys: With application to mortality linked NHANES III Phase II genetic data.

The Cox proportional hazards (PH) model is a common statistical technique used for analyzing time-to-event data. The assumption of PH, however, is not always appropriate in real applications. In cases where the assumption is not tenable, threshold regression (TR) and other survival methods, which do not require the PH assumption, are available and widely used. These alternative methods generally assume that the study data constitute simple random samples. In particular, TR has not been studied in the setting of complex surveys that involve (1) differential selection probabilities of study subjects and (2) intracluster correlations induced by multistage cluster sampling. In this paper, we extend TR procedures to account for complex sampling designs. The pseudo-maximum likelihood estimation technique is applied to estimate the TR model parameters. Computationally efficient Taylor linearization variance estimators that consider both the intracluster correlation and the differential selection probabilities are developed. The proposed methods are evaluated by using simulation experiments with various complex designs and illustrated empirically by using mortality-linked Third National Health and Nutrition Examination Survey Phase II genetic data.

Multivariate piecewise exponential survival modeling.

In this article, we develop a piecewise Poisson regression method to analyze survival data from complex sample surveys involving cluster-correlated, differential selection probabilities, and longitudinal responses, to conveniently draw inference on absolute risks in time intervals that are prespecified by investigators. Extensive simulations evaluate the developed methods with extensions to multiple covariates under various complex sample designs, including stratified sampling, sampling with selection probability proportional to a measure of size (PPS), and a multi-stage cluster sampling. We applied our methods to a study of mortality in men diagnosed with prostate cancer in the Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial to investigate whether a biomarker available from biospecimens collected near time of diagnosis stratifies subsequent risk of death. Poisson regression coefficients and absolute risks of mortality (and the corresponding 95% confidence intervals) for prespecified age intervals by biomarker levels are estimated. We conclude with a brief discussion of the motivation, methods, and findings of the study.

Prevalence and Patterns of Insomnia Symptoms Among People Aged 65 and Above in Guangdong Province, China.

Objective: This survey investigated the prevalence, distribution, and correlative factors of insomnia symptoms among people aged 65 and above in Guangdong Province, China. Methods: The Guangdong Mental Health Survey was conducted on the elderly in all 21 cities of Guangdong Province from September to December 2021. Multistage stratified cluster sampling was adopted, and 16 377 adult residents were interviewed face-to-face, from which 4001 elderly participants aged 65 and above were included for this study. Complex weighted adjustment methods were applied to weight the data. Multinomial logistic regression was applied to test the independent associations of clinical insomnia symptoms (CIS) and subthreshold insomnia symptoms (SIS) with the factors. Results: The pooled estimate of insomnia symptoms was 13.44% [95% confidence interval (CI): 12.2 %-14.7%]. The 1-month weighted prevalence of SIS and CIS were 11.15% (95% CI: 10.05%-12.37%) and 2.28% (95%CI: 1.77%-2.94%), respectively. Multinomial logistic regression analysis revealed that urban residence, irregular diet, low body mass index, chronic disease, napping 3-4/week, early changes in dementia, symptoms of subthreshold depression, subthreshold generalized anxiety, and generalized anxiety disorder were positively associated with SIS. Additionally, living in urban areas, having chronic diseases, symptoms of subthreshold depression, major depressive disorder, subthreshold generalized anxiety, generalized anxiety disorder were positively associated with CIS. Conclusion: Insomnia symptoms, including CIS and SIS, were prevalent among the elderly in Guangdong Province. Given the high burden of CIS and SIS, policymakers and healthcare professionals must explore and treat the related factors accordingly.

A study on the applicability of one-step vortex extraction and purification combined with gas chromatography-tandem mass spectrometry for analysis of four skin penetration enhancers in cosmetics.

Based on one-step vortex extraction and purification combined with gas chromatography-tandem mass spectrometry (GC-MS/MS), we established a simple, rapid, and efficient method for the simultaneous determination of four skin penetration enhancers in cosmetics, including isosorbide dimethyl ether, isopropyl myristate, N-butylsaccharin and Azone. The extraction procedure was performed in a centrifuge tube, allowing extraction and purification in a single step. The cosmetic sample was extracted by n-hexane-ethyl acetate (1:1, V/V), purified by silica gel and anhydrous magnesium sulfate as the solid phase purification agent, separated on a TG-5 ms column (30.0 m × 0.25 mm × 0.25 µ m), confirmed and detected by GC-MS/MS in the selected reaction monitoring (SRM) mode, and quantified by the internal standard method with Di-n­butyl phthalate-D4(DBP-D4) as the internal standard. The selections of a column, extraction solvent, and solid phase purification agent were optimized. Under the optimized conditions, the four skin penetration enhancers showed good linearities in the range of 0.02∼0.50 mg L - 1. The correlation coefficients (r) were 0.992 ∼ 0.997, exceeding the specifications requirements (r ≥ 0.990); The detection (LODs, S/N = 3) and quantification limits (LOQs, S/N = 10) of the method were 0.08 ∼ 0.12 mg kg-1 and 0.25 ∼ 0.40 mg kg-1, respectively. According to the cosmetic matrix in different formulation systems, the spiked recovery tests were carried out at three levels, i.e., low, medium, and high. The average recoveries of the analytes were 85.3% ∼ 95.6%, and the relative standard deviations (RSDs, n = 6) were 2.1% ∼ 7.8%. The established method was also employed to analyze cosmetics in the market. Azone, isosorbide dimethyl ether, and isopropyl myristate resulted as the most widely used skin penetration enhancers in cosmetics. The method established in this study has the advantages of operational simplicity, high sensitivity, good reproducibility, and low consumption of samples and solvents. Moreover, it can be used to determine skin penetration enhancers in cosmetics.

Emergency medical service personnel' post-traumatic stress disorder and psychological detachment: The mediating role of presenteeism.

Background: Emergency medical service personnel are subjected to various stressors, which makes them more likely to develop post-traumatic stress disorder symptoms. Studies have shown that psychological detachment and presenteeism play a role at the level of post-traumatic stress disorder. There is no study to examine the relationship between psychological detachment, presenteeism, and post-traumatic stress disorder among emergency medical service personnel. Objective: The main objective of the study is to investigate the effects of presenteeism in explaining the relationship between psychological detachment and post-traumatic stress disorder among emergency medical service personnel. Design: A cross-sectional study was conducted among 836 emergency medical service personnel in 51 counties and cities in Hunan Province, China. Methods: They were anonymously investigated by using the Impact of Event Scale-Revised (IES-R), the Stanford Presenteeism scale-6 (SPS-6), and the Psychological Detachment Scale. Statistic description, univariate analysis, pearson correlation, and structural equation model were adopted to analyze the data. Results: The mean score of IES-R, SPS-6, and the psychological detachment scale were 22.44 ± 16.70, 15.13 ± 4.20, and 11.30 ± 4.24. Post-traumatic stress disorder was positively relevant with presenteeism (r = 0.381, p< 0.01), but negatively correlated with psychological detachment (r = -0.220, p < 0.01). And presenteeism partially mediated the association between psychological detachment and post-traumatic stress disorder. Conclusions: The results show a high prevalence of post-traumatic stress disorder symptoms in EMS personnel, presenteeism can statistically significantly predict post-traumatic stress disorder symptoms. If hospital management can reduce the presenteeism of emergency medical service personnel, this will help them reduce post-traumatic stress disorder symptoms.

Prevalence and patterns of major depressive disorder and subthreshold depressive symptoms in south China.

BACKGROUND: Information on major depressive disorder (MDD) and subthreshold depressive symptoms (SDS) is rarely reported in south China. This study examines the prevalence rates and patterns of MDD and SDS of a large representative sample of adult residents in south China. METHODS: The Guangdong Mental Health Survey was conducted on adults (over 18 years) from September to December 2021. Multistage stratified cluster sampling was used and face-to-face interviews were done with a two-stage design by trained lay interviewers and psychiatrists. A total of 16,377 inhabitants were interviewed using standardized assessment tools. Data were weighted to adjust for differential probabilities of selection and differential response. RESULTS: The weighted prevalence rates of MDD and SDS were 2.5 % (95%CI: 2.2 %-2.9 %) and 14.7 % (95%CI: 14.0 %-15.5 %), respectively. Multinomial logistic regression analysis revealed that female, younger age, living in urban area, higher education, unmarried, irregular meal pattern, lack of physical exercise, chronic diseases, irregular napping pattern and short sleep were positively associated with SDS. Besides, female, younger age, unmarried, irregular meal pattern, lack of physical exercise, chronic diseases, short sleep and poor mental health were positively associated with MDD. LIMITATIONS: The cross-sectional nature of the study limited causal inferences. CONCLUSIONS: The prevalence of MDD in Guangdong province in 2021 is higher than in mainland China in 2013. Given the higher prevalence of SDS, and high burden of depression, it also offers valuable opportunities for policymakers and health-care professionals to explore the factors affecting mental health in Guangdong province, especially during the COVID-19 epidemic.

Strategies and progresses for enhancing targeted antibiotic delivery.

Antibiotic resistance is a global health issue and a potential risk for society. Antibiotics administered through conventional formulations are devoid of targeting effect and often spread to various undesired body sites, leading to sub-lethal concentrations at the site of action and thus resulting in emergence of resistance, as well as side effects. Moreover, we have a very slim antibiotic pipeline. Drug-delivery systems have been designed to control the rate, time, and site of drug release, and innovative approaches for antibiotic delivery provide a glint of hope for addressing these issues. This review elaborates different delivery strategies and approaches employed to overcome the limitations of conventional antibiotic therapy. These include antibiotic conjugates, prodrugs, and nanocarriers for local and targeted antibiotic release. In addition, a wide range of stimuli-responsive nanocarriers and biological carriers for targeted antibiotic delivery are discussed. The potential advantages and limitations of targeted antibiotic delivery strategies are described along with possible solutions to avoid these limitations. A number of antibiotics successfully delivered through these approaches with attained outcomes and potentials are reviewed.

Low mental health literacy and its association with depression, anxiety and poor sleep quality in Chinese elderly.

BACKGROUND: Mental health literacy (MHL) is rarely reported in the Chinese elderly. This study explored the pattern of MHL in the Chinese elderly in relation to depression, anxiety and poor sleep quality. METHODS: A cross-sectional study was conducted among older adults in Guangzhou, south China. Participants were investigated face-to-face using the Chinese National Mental Health Literacy Scale, the Patient Health Questionnaire-9 item (PHQ-9), the 7-item Generalized Anxiety Disorder (GAD-7) and the Pittsburgh Sleep Quality Index (PSQI). Mental Health Literacy Scale contains three dimensions: mental health knowledge, mental health skills (such as social support, cognitive reappraisal and attentional distraction) and mental health awareness. Multivariate logistic regression was used for examining the association between MHL and mental health. RESULTS: A total of 506 older adults were recruited. The percentage of depression, anxiety, and poor sleep quality were 16.6%, 7.9% and 40.9%, respectively. MHL dimensions independently associated with depression included cognitive reappraisal (OR = 1.95, p < .001), attentional distraction (OR = 0.61, p = 0.044) and awareness (OR = 0.56, p = 0.027). MHL dimensions independently associated with anxiety symptoms included cognitive reappraisal (OR = 1.90, p = 0.011) and attentional distraction (OR = 0.44, p = 0.016). MHL dimensions independently associated with poor sleep quality included social support (OR = 0.75, p = 0.022), cognitive reappraisal (OR = 1.55, p = 0.003) and attentional distraction (OR = 0.65, p = 0.016). CONCLUSION: Given the low MHL and its association with poor mental health in the Chinese elderly, policymakers and health professionals should improve the older adults' MHL, which could be conducive to the prevention and control of their mental health problems.

Impaired CD8+ T cells in term pregnancy decidua with chronic hepatitis B virus infection.

PROBLEM: Hepatitis B virus (HBV) infection is more likely to develop a state of chronicity in early life, particularly mother-to-child transmission (MTCT) of HBV in the fetus during pregnancy. Till now, little is known about the impact of chronic HBV infection on the immune status of the maternal-fetus interface, and the immune profile of placental lymphocytes in MTCT of HBV is poorly understood. METHOD OF STUDY: Thirteen term pregnant women with chronic HBV infection (HBV-PW) and thirteen normal pregnant women as healthy control (HC-PW) were enrolled. The profile of placental immune cells and paired peripheral blood were analyzed by flow cytometry and immunohistochemistry. RESULTS: Compared with HC-PW, the frequency of CD8+ T cells from the term placenta of HBV-PW was significantly reduced. These cells showed decreased expression of activation molecules CD69 and HLA-DR; thus, decidual CD8+ T cells from HBV-PW demonstrated hypofunctional signature as evidenced by significantly reduced production of IFN-γ, as well as compromised ability of degranulation and proliferation. CONCLUSIONS: These findings supported that hypoactivated decidual CD8+ T cells might possess compromised ability in chronically HBV-infected term pregnant women. Our study provides robust evidence for the necessity and importance of antiviral intervention in HBV-PW to prevent MTCT of HBV.

Integrated Bioinformatics Analysis for Identifying the Significant Genes as Poor Prognostic Markers in Gastric Adenocarcinoma.

Gastric adenocarcinoma (GAC) is the most common histological type of gastric cancer and imposes a considerable health burden globally. The purpose of this study was to identify significant genes and key pathways participated in the initiation and progression of GAC. Four datasets (GSE13911, GSE19826, GSE54129, and GSE79973) including 171 GAC and 77 normal tissues from Gene Expression Omnibus (GEO) database were collected and analyzed. Through integrated bioinformatics analysis, we obtained 69 commonly differentially expressed genes (DEGs) among the four datasets, including 20 upregulated and 49 downregulated genes. The prime module in protein-protein interaction network of DEGs, including ADAMTS2, COL10A1, COL1A1, COL1A2, COL8A1, BGN, and SPP1, was enriched in protein digestion and absorption, ECM-receptor interaction, focal adhesion, PI3K-Akt signaling pathway, and amoebiasis. Furthermore, expression and survival analysis found that all seven hub genes were highly expressed in GAC tissues and 6 of them (except for SPP1) were able to predict poor prognosis of GAC. Finally, we verified the 6 high-expressed hub genes in GAC tissues via immunohistochemistry, Western blot, and RNA quantification analysis. Altogether, we identified six significantly upregulated DEGs as poor prognostic markers in GAC based on integrated bioinformatical methods, which could be potential molecular markers and therapeutic targets for GAC patients.

Protein S-nitrosylation regulates proteostasis and viability of hematopoietic stem cell during regeneration.

Hematopoietic stem cells (HSCs) regenerate blood cells upon hematopoietic injuries. During homeostasis, HSCs are maintained in a low reactive oxygen species (ROS) state to prevent exhaustion. However, the role of nitric oxide (NO) in controlling HSC regeneration is still unclear. Here, we find increased NO during HSC regeneration with an accumulation of protein aggregation. S-nitrosoglutathione reductase (GSNOR)-deleted HSCs exhibit a reduced reconstitution capacity and loss of self-renewal after chemotherapeutic injury, which is resolved by inhibition of NO synthesis. Deletion of GSNOR enhances protein S-nitrosylation, resulting in an accumulation of protein aggregation and activation of unfolded protein response (UPR). Treatment of taurocholic acid (TCA), a chemical chaperone, rescues the regeneration defect of Gsnor-/- HSCs after 5-fluorouracil (5-FU) treatment. Deletion of C/EBP homologous protein (Chop) restores the reconstitution capacity of Gsnor-/- HSCs. These findings establish a link between S-nitrosylation and protein aggregation in HSC in the context of blood regeneration.

[Study on pharmacokinetics of matrine by intramuscular administration in rat].

OBJECTIVE: To study the pharmacokinetics of matrine (MT) intramuscular administration in rat. METHOD: Plasma concentration of matrine was determined by HPLC under the following conditions: column (Shim-pack VP-ODS, 4. 6 mm x 150 mm, 5 m); eluent (acetonitrile-0.02 mol ammonium acetate buffer-triethylamine 30: 70: 0.04); flow rate was 1 mL x min(-1) and ultraviolet detection wavelength was set at 220 nm; column temperature 40 degrees C; aliquot injected 20 microL. All data of concentration-time of matrine were treated with pharmacokinetics program DAS 2. 1. 1. RESULT: A simple, sensitive and reliable method for determining matrine in rat plasma by HPLC was established. The plasma concentration time profiles of MT fitted in with two-compartment models well, and the main pharmacokinetic parameters found for MT after i. m. infusion were as follows: C(max) = 21.113 9 mg x L(-1), t(max) = 0.75 h, t1/2alpha 1.34 h, t1/2beta = 3.509 h, AUC(0-t) = 90.984 mg x h(-1) x L(-1), AUC(0-infinity) = 100.346 mg x h(-1) x L(-1). CONCLUSION: Compare with oral administration, the matrine is absorbed well and distributes fast with intramuscular administration; the absolute bioavailability of matrine is higher. According to this, the pharmacological action is also stronger and duration is longer.

[Effect of ceftiofur hydrochloride on pharmacokinetics of matrine in rats].

OBJECTIVE: To investigate the effect of ceftiofur hydrochloride on the pharmacokinetics of matrine in rats. METHOD: The rats were divided into two groups: one group was administrated with matrine only (control group) and the other was administrated with matrine in combination with ceftiofur hydrochloride. HPLC-UV method was used for determining the plasma concentration of matrine in both groups. The pharmacokinetic parameters were calculated from the plasma concentration-time data using the DAS 2. 1. 1 software program. RESULT: The main pharmacokinetic parameters for the control group were C(max) = 21.113 9 mg x L(-1), T(max) = 0.75 h, t1/2alpha = 1.34 h, t1/2beta = 3.509 h, AUC(0-t) = 90.984 mg x h(-1) x L(-1) and AUC(0-inifinity) = 100.346 mg x h(-1) x L(-1), and the data for the combination group were C(max) = 11.707 mg x L(-1), T(max) = 0.917 h, t1/2alpha = 1.598 h, t1/2beta = 3.247 h, AUC(0-t) = 53.28 mg x h(-1) x L(-1) and AUC(0-inifinity) = 60.035 mg x h(-1) x L(-1). CONCLUSION: The plasma concentration of matrine and bioavailability in combination group were significantly lower than those of the control group. In combination group, matrine had a higher clearance and volume of distribution in the central compartments, as well as a lower volume of distribution in the peripheral compartments.

Carbon quantum dots derived from the extracellular polymeric substance of anaerobic ammonium oxidation granular sludge for detection of trace Mn(vii) and Cr(vi).

Carbon quantum dots (CQDs) were synthesized via a hydrothermal method, in which extracellular polymeric substance (EPS) from anaerobic ammonium oxidation (anammox) granular sludge was used as a carbon precursor, while citric acid and ethylenediamine were applied as auxiliary carbon source and passivation agent, respectively. The synthesized CQDs, with orderly spherical shape and mean size of 7.15 nm, emitted blue fluorescent light under UV radiation of 365 nm. The CQDs had a high fluorescence yield (40.84%), with good water solubility and excellent spectroscopic properties. In addition, the CQDs exhibited selective, sensitive and distinctive fluorescence quenching behaviors for Cr(vi) and Mn(vii) in a PBS buffer solution (NaH2PO4-Na2HPO4) of pH 7, with a detection limit of 5.8 nM for Cr(vi) and 2.3 nM for Mn(vii). Owing to the nitrogen components from the EPS of anammox granules, the CQDs were well nitrogen-doped, promoting electron-transfer and leading to reduction between the CQDs and Mn(vii)/Cr(vi). These results indicate that CQD-based chemical sensing is a simple and efficient means for the fluorescence detection of Mn(vii) and Cr(vi).

Zero-valent iron-manganese bimetallic nanocomposites catalyze hypochlorite for enhanced thallium(I) oxidation and removal from wastewater: Materials characterization, process optimization and removal mechanisms.

Nano zero-valent metals adsorption coupled with advanced oxidation for environmental pollutants removal has been gaining attention recently. In this study, zero-valent iron-manganese (nZVIM) bimetallic nanocomposites were prepared via one-pot borohydride reduction and coupled with hypochlorite (ClO-) oxidation for enhanced thallium (Tl) removal from wastewater. Amorphous nZVIM nanoparticles were successfully synthesized, with a specific surface area of 106.89 m2/g, and a saturation magnetization of 65.16 emu/g. In comparison with the nZVIM adsorption or ClO- oxidation alone, the hybrid nZVIM/ClO- process achieved much faster Tl(I) removal rate over a wide pH range from 6 to 10. Maximum Tl(I) removal capacity was as high as 990.0 mg/g. The oxidation-induced adsorption for Tl(I) removal well followed the pseudo-first kinetic order model. Stable and effective adsorbent regeneration was achieved during the cyclic adsorption-desorption tests. This process also had high resistance to the interference of external cations, can act as an effective pretreatment for Tl(I) removal from the actual saline industrial wastewater. The main mechanisms for Tl(I) removal were found to be oxidation, surface precipitation, pore retention, and surface complexation. The nZVIM coupled with ClO- approach has great potential for Tl(I) removal from wastewater, and its application in other fields is highly anticipated.

Enhanced thallium(I) removal from wastewater using hypochlorite oxidation coupled with magnetite-based biochar adsorption.

The development of efficient and regenerable adsorbent coupled with advanced oxidation for enhanced thallium (Tl) removal has been a recent focus on wastewater treatment. In this study, a magnetite-based biochar derived from watermelon rinds was synthesized and used as a sustainable adsorbent and catalyst for hypochlorite oxidation and removal of Tl(I) from wastewater. The addition of hypochlorite substantially enhanced the Tl(I) removal under normal pH range (6-9). Maximum Tl adsorption capacity of 1123 mg/g was achieved, which is 12.3% higher than the highest value previously reported. The magnetic biochar can be regenerated using 0.1 mol/L HNO3 solution for elution in only 5 min, with a Tl desorption efficiency of 78.9%. The Tl removal efficiency was constantly higher than 98.5% during five consecutive recycle tests, indicating the effective reuse performance of the adsorbent. Oxidation, surface precipitation, pore retention and surface complexation were the main mechanisms for Tl(I) removal. The re-dissolution of Tl compounds and ion exchange of Tl cations with proton were the main mechanisms for adsorbent regeneration. Given the fast oxidation rate, high adsorption capacity, steady reusability and facile separability, this magnetic biochar-hypochlorite technique is a promising means for Tl(I) removal from wastewater. The catalytic hypochlorite oxidation induced by the magnetic biochar has also great potential to the effective removal of other pollutants.